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Biomedical subjects

J Nieminen

Publications and source records attributed to J Nieminen.

At least 19 recordsLinked to original sources
PubMed2006

Randomized clinical trial of Lichtenstein patch or Prolene Hernia System for inguinal hernia repair.

BACKGROUND: In this randomized prospective study the short- and long-term outcomes of patients undergoing inguinal hernia repair with either Lichtenstein mesh or the Prolene Hernia System (PHS) were evaluated. METHODS: Postoperative pain and time to return to work, driving and sporting hobbies were recorded after 300 inguinal hernia repairs done by one of the two methods. Long-term sequelae and complications were assessed at follow-up visits 1 week, 1 month and 1 year after the operation. RESULTS: The median duration of operation for unilateral primary hernia was 37 min for the Lichtenstein operation and 27 min for the PHS procedure (P < 0.001). Postoperative pain was similar after both operations. Median sick leave was 7 days in both groups. Time to driving a car was 4 versus 3 days, and time to return to sporting hobbies 13 versus 11 days, in the Lichtenstein and PHS groups, respectively. Apart from a residual femoral hernia after Lichtenstein repair, no recurrent inguinal hernias were detected. CONCLUSION: Both Lichtenstein and PHS methods resulted in rapid recovery and low recurrence rates. The PHS operation was significantly quicker.

Adult↗
PubMed2005

Abnormal response to physical activity in femurs after heterozygous inactivation of one allele of the Col2a1 gene for type II collagen in mice.

The objective of this study was to evaluate the influence of heterozygous inactivation of one allele of the type II collagen gene (Col2a1) on biomechanical properties and mineral density of bone under physical loading conditions. C57BL/6-TGN mice with heterozygous knockout (HZK) inactivation of Col2a1 gene and their nontransgenic littermate controls were housed in individual cages with running wheels for 9 and 15 months. The running activity of each mouse was monitored continuously throughout the experiment. Bone mineral density (BMD) of mice femora was measured using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computerized tomography (pQCT). Biomechanical properties were determined using three-point bending tests. Vertebral bone samples were prepared for quantitative polarized light microscopy and digital densitometry of proteoglycans. The concentration of total collagen and collagen cross-links were analyzed using high-performance liquid chromatograpy (HPLC). The average daily running distance was shorter for the HZK mice between the age of 4 and 15 months as compared with normal runners (P < 0.05). The ultimate breaking force was 14.8% and 23.6% (9 vs. 15 months) lower in HZK-runners than in wild-type runners. BMD of the femur was 6.1% lower in HZK-runners at the age of 9 months (P < 0.05). Physical activity increased cortical BMD in wild-type runners but not in the HZK runners at the age of 9 months. The collagen network of the HZK mice was less organized. There were only minor changes in BMD and mechanical and structural properties between sedentary HZK mice and their wild-type controls. Increased physical activity induced significantly lower bone density, mechanical properties, and organization of collagen fibers in male HZK mice. However, there were no major differences in biomechanical parameters between sedentary HZK and wild-type male mice. This suggests an important guiding role of collagen type II in bone remodelling and maturation.

Animals↗
PubMed2004

Functional treatment of closed humeral shaft fractures.

We treated 93 consecutive patients, average age 53 (16-90) years, with closed humeral shaft fractures applying a functional brace immediately after injury. Seventy-two (77%) fractures healed without problems. There were significantly more consolidation problems in fractures in the proximal third (46% consolidated) compared to those at the middle (81% consolidated) and distal third (86% consolidated) of the shaft. Logistic regression analysis revealed the only predictive factor in respect to successful brace treatment was fracture location. No significant difference was found in respect to healing between different AO-type fractures.

Adolescent↗
PubMed2001

Premature vertebral endplate ossification and mild disc degeneration in mice after inactivation of one allele belonging to the Col2a1 gene for Type II collagen.

STUDY DESIGN: Skeletal tissues of mice with an inactivated allele of the Col2a1 gene for Type II collagen ("heterozygous knockout") were studied. OBJECTIVE: To determine whether a heterozygous inactivation of the Col2a1 gene has a role in the etiology of spine disorders such as disc degeneration. SUMMARY OF BACKGROUND DATA: Mutations in the COL2A1, COL11A1, COL11A2, and COL9A2 genes have been linked to spine disorders. However, the mechanism by which genetic factors lead to disc degeneration still are largely unknown. METHODS: Spine tissues were studied using radiograph analyses; conventional, quantitative, and polarized light microscopy; immunohistochemistry for the major extracellular components, and in situ hybridization for procollagens alpha1(I) and alpha1(II). Voluntary running activity also was monitored in half of the mice. RESULTS: As the findings showed, 1-month-old heterozygous knockout mice had shorter limb bones, skulls, and spines, as well as thicker and more irregular vertebral endplates, which calcified earlier than in the control mice. They also had a lower concentration of glycosaminoglycans in the anulus fibrosus, in the endplates, and in the vertebral bone than the controls. These features in the heterozygous knockout mice were compensated by the age of 15 months. However, the long bones and skulls of the mature heterozygous mice remained shorter than those of the controls. Gene-deficient mice used the running wheel less. However, physical exercise did not induce any marked structural changes in the skeleton. CONCLUSION: Mice with heterozygous knockout of Col2a1 show subtle early skeletal manifestations that bear some resemblance to those of human spine disorders.

Aging↗
PubMed2000

Efficacy and tolerability of fluticasone propionate nasal drops 400 microgram once daily compared with placebo for the treatment of bilateral polyposis in adults.

BACKGROUND: Chronic eosinophilic rhinosinusitis underlies a range of respiratory disorders including nasal polyposis. Surgical and medical methods are used to control polyps, with topical steroids commonly being used for their anti-inflammatory properties. Fluticasone propionate nasal drops (FPND) is a formulation developed specifically for an effective and well tolerated corticosteroid treatment of nasal polyposis. OBJECTIVES: To assess efficacy and tolerability of FPND in the treatment of bilateral nasal polyposis in adults. METHODS: This multicentre, randomized, parallel-group study compared FPND 400 microgram once daily (o.d.) with placebo for 12 weeks in adult patients with mild to moderate bilateral polyposis. The primary efficacy endpoint was visual assessment of polyp size by the physician at monthly clinic visits. Nasal blockage, rhinitis, peak nasal inspiratory flow (PNIF), olfactory function and requirement for polypectomy were also assessed at visits. The patients kept diary card records of symptoms, PNIF, and use of rescue antihistamine. Additional safety data were provided by a 12-week open extension, when all patients received FPND 400 microgram o.d. RESULTS: After 12 weeks double-blind treatment with FPND (n = 52) or placebo (n = 52), polyp size was reduced in 27% and 16% of patients, respectively; clinical reduction of nasal blockage significantly favoured FPND over placebo (55% vs 22%; P = 0.002), and clinic PNIF had increased significantly with FPND (by 52 L/min vs -3 L/min for placebo; P < 0.001). Diary card measurements showed significant benefits of FPND vs placebo for daily PNIF, nasal blockage, rhinitis and use of loratadine rescue medication. Both treatments were well tolerated and no serious adverse events occurred during randomized treatment. Epistaxis was more frequent with FPND than placebo but was generally mild and did not result in withdrawals. Mean serum cortisol levels did not change significantly with either treatment. CONCLUSION: This study showed FPND 400 microgram o.d. to be an effective and well tolerated treatment for bilateral nasal polyposis in adults.

Administration, Topical↗
PubMed1999

Do more highly organized collagen fibrils increase bone mechanical strength in loss of mineral density after one-year running training?

The aim of this study was to evaluate the effects of long-term running training on the structural properties of bone. Ten beagle dogs ran according to a strenuous progressive program (up to 40 km/day) for 1 year. At the end of the training program, there was a significant reduction in bone mineral density (up to 9.7%) in the vertebrae of the runner dogs as compared with 10 sedentary control dogs. Polarized light microscopy of the vertebral trabecular bone, however, displayed proportionally higher retardation values of the collagen network of the runner dogs than of the sedentary dogs, suggesting a reorganization in a more parallel manner in the collagen fibrils. The concentration and cross-linking of collagen in the bones remained similar in both groups. No differences were observed in the force to failure of bones of the two groups nor in the histomorphometric analysis of the bones. We suggest that the collagen network in the bones accounted for the maintenance of the strength properties in the bones of the runner dogs despite the loss of mineral density.

Animals↗
PubMed1998

Subchondral bone remodeling increases in early experimental osteoarthrosis in young beagle dogs.

We evaluated subchondral bone remodeling and structure in the condyles of the femur and the patellar surface of the femur in early experimental osteoarthrosis of young female beagle dogs. 14 littermate (twin) dogs were divided into operation (n 7) and control groups (n 7). The dogs in the operation group underwent surgically a 30 degrees valgus angulation of the right tibia to induce osteoarthrotic articular cartilage lesions in the knee (stifle) joint. 7 months postoperatively, bone samples were harvested from both condyles and the patellar surface of the femur and evaluated by histomorphometry of subchondral bone. Cartilage samples from the same areas were taken for histology. In the operated dogs, subchondral bone remodeling increased strikingly in the patellar surface of the femur; osteoid thickness and osteoblast surface/bone surface increased up to 42% and 94% (p < 0.05), as compared to controls. Total and active erosion depths increased by 14% and 30% in the same area (p < 0.05). However, in bone structural parameters no significant difference could be observed between the groups. In the medial condyle of the femur, the trabecular number decreased in operated dogs, as compared to controls (p < 0.05). The lateral condyle of the femur in operated animals did not differ from controls in the parameters tested. In the operated dogs, histology from cartilage samples showed initial osteoarthrotic changes in the patellar surface and the medial condyle of the femur. Histologic changes were greatest in the patellar surface of the femur, as assessed by the Mankin scores. At the very onset of osteoarthrosis, subchondral bone remodeling increases, but the bone structural changes are indistinct. It seems that in this osteoarthrosis model, cartilage lesions precede major subchondral changes in the structure of the bone.

Animals↗
PubMed1995

Comparison of different models for interpreting bone mineral density measurements using DXA and MRI technology.

Bone mineral density measurements using dual X-ray absorptiometry (DXA) are commonly expressed as areal density (g/cm2). However, areal BMD (BMDareal) is dependent on bone size and this can lead to erroneous interpretations of BMD values. We have previously presented a simple method for calculating apparent volumetric bone mineral density (BMDvol) using ancillary DXA-derived data. In the present study we tested the validity of our model using in vivo volumetric data obtained from magnetic resonance imaging (MRI) of lumbar vertebrae. BMDareal and BMDvol of L3 were measured from sixteen pairs of identical twins (24 men, 8 women), aged 25-69 years. The dimensions of the lumbar vertebra L3 were measured from MR images and BMD values were corrected for these dimensions. The DXA-derived apparent volumetric bone mineral density (BMDvol) correlated moderately with MRI-derived BMDs (r values from 0.665 to 0.822). In contrast to BMDareal, BMDvol and MRI-derived BMDs were not related to body size variables. All these volume-corrected BMDs diminished the erroneous effect of vertebral size on areal BMD. We conclude that the simple DXA-derived BMDvol can be used for normalization of bone mineral density values in subjects of different body sizes, and especially in growing children.

Absorptiometry, Photon↗
PubMed1995

Long-distance running alters bone anthropometry, elemental composition and mineral density of young dogs.

Ten young beagle dogs were run on a treadmill for 1 year, the last 15 weeks 40 km/day. Thereafter bone anthropometric variables, elemental composition, mineral density (BMD) and serum markers of bone metabolism were analyzed and compared with matched-paired control dogs. More osteophytes developed, weight-bearing bones grew larger and BMD of axial skeleton was reduced in the trained group. Zinc and sodium accumulated in bones of the runners. Zinc correlated negatively with BMD. Serum osteocalcin and C-terminal propeptide of type I procollagen did not correlate with the observed differences in BMD. This experiment implies that intensive endurance training in adolescence may reduce the peak bone mass and alter the structural properties of bone.

Animals↗
PubMed1995

Estimation of spinal bone density using conventional MRI. Comparison between MRI and DXA in 32 subjects.

We evaluated the usefulness of MRI T1 and T2 relaxation times in assessing bone mineral status. T1 and T2 relaxation times of L3 were measured in 16 pairs of identical twins (24 men, 8 women), aged 25-69 years. Bone mineral density (BMD), bone mineral content (BMC) and apparent volumetric bone mineral density (BMDvol) of L3 were measured from the same subjects using dual x-ray absorptiometry (DXA). T2 relaxation time correlated inversely with BMD and BMC (r -0.40 and r -0.47, respectively), whereas a significant positive correlation between T1 relaxation time and BMDvol was found (r 0.36). The measurement of T1 may give some information on bone mineral status in clinical MRI measurements when DXA is not available. It is possible that T1 and T2 reflect not only bone density, but also other factors related to bone structure.

Absorptiometry, Photon↗
PubMed1992

Endurance training associated with slightly lowered serum estradiol levels decreases mineral density of canine skeleton.

The effects of long-term running exercise were studied in 20 beagle dogs. A total of 10 dogs ran from the age of 15 weeks to the age of 70 weeks in a progressive program for up to 40 km/day. A total of 10 sister dogs spent the study period in individual cages. When the dogs were 70 weeks old, bone mineral density of the vertebrae, hip, and radius was analyzed by dual-energy x-ray absorptiometry (DEXA; Lunar) and the vertebrae were also assessed by quantitative computed tomography (QCT; Siemens DR 1). Mineral density was lower in the running dogs than in the controls. The difference was greatest in the spine in the QCT analysis. Blood chemistry analyses revealed that the metabolism of the bone was significantly accelerated. The estradiol levels showed the trend to be reduced in the running group. The beneficial effect of exercise on mineral density has been shown in many earlier studies. However, in this study we demonstrate the possibility of adverse effects of long-term exercise on bone tissue. The change was associated with a decrease of serum estradiol level.

Alkaline Phosphatase↗
PubMed1991

Effects of long-term running on spinal mineral content in dogs.

The effects of long-term running were studied in 20 beagle dogs. Ten dogs ran from the age of 15 weeks to the age of 70 weeks in a progressive program for up to 40 km/day. Ten sister dogs spent the same time in individual cages. At the age of 70 weeks the spines of the dogs were studied with regard to mineral density using dual-energy X-ray absorptiometry and quantitative computed tomography. Mineral density was lower in the running dogs than in the controls.

Animals↗
PubMed1981

Haemodynamic changes after portal vein ligation and mesocaval interposition "H" grafting in the dog.

The haemodynamic effects of portal ligation combined with mesocaval H-grafting were evaluated experimentally as follows: acute portal hypertension was induced in 20 mongrel dogs by ligation of the portal vein, in 15 of these a mesocaval shunt was constructed using an autogenous venous segment, the rest served as controls and were left without shunting. All animals with portal occlusion only died within 80 minutes, whereas nine dogs in the H-graft groups survived. The one-month patency rate was 78 per cent. Slight portal hypertension was observed only in the early post-shunt period, one month later the pressure was normal. By this time the flow through the shunt was significantly reduced and numerous but small portosystemic collaterals were visualized radiographically. Varices formation was not observed. The Xe-133 wash-out of the liver and liver pO2 were normal in the early post-shunt period. These findings were in marked contrast to those in the control group where both variables showed rapid deterioration. The pre-shunt spleen flow proved to be of prognostic significance: poor flow was associated with bad prognosis. After one month the liver flow was decreased whereas the spleen flow was increased, perhaps indicating increased splenocollateral flow. Portal ligation combined with mesocaval H-grafting thus seemed to induce slight and temporary portal hypertension in this model. This appeared to be caused by relatively narrow lumen of the shunt. Normotension was soon established by rapid opening up of portosystemic collaterals.

Animals↗
PubMed1979

Gonococcal perihepatitis in a surgical ward.

Within a three-year period six female patients with gonococcal perihepatitis were encountered. In the acute stage they had clinical symptoms indistinguishable from acute cholecystitis. In all six patients the diagnosis was established by positive growth of Neisseria gonorrhoeae from cervix specimens. Evidence of previous gonococcal pelvic infection was disclosed in three of the patients. In two patients the gonococcal aetiology of the disease was suggested by papular skin lesion and arthritis. Of the annual mean number of patients admitted to the emergency ward with suspicion of acute cholecystitis within the same three year period, 2.6% presented with gonococcal perihepatitis. As the incidence of gonorrhoea is increasing, complications such as perihepatitis are seen more frequently among young female patients admitted to surgical emergency wards because of acute abdominal pains.

Adult↗
PubMed1979

Liver damage after liver hilus dearterialization in dogs.

Twenty-one harrier dogs underwent a standardized liver hilus dearterialization with (7) or without (14) cholecystectomy using six sham-operated dogs as controls. Seven dogs died, only one of which was in the dearterialization and cholecystectomy group. S-OCT and s-GDH were increased at 90 minutes after dearterialization. There was no statistical difference between the groups at 90 minutes. On the first day after dearterialization, the activity of s-OCT, s-GDH, s-ALAT rose significantly (p less than 0.005). The activity of s-ASAT was, however, increased to the same extent both in the dearterialized and the sham-operated animals. A normalization of the serum enzyme activities was usually seen after one week. S-ALP increased on the first day (p less than 0.005) and still higher values were noted on the seventh day after dearterialization. Cholecystectomy did not affect any of these results except mortality. Liver oxygen consumption, in vitro was unchanged throughout the experiment. The oxygen consumption of bile duct mucosal scrapings one week after dearterialization was similar to the corresponding values in the controls. The results indicate that the dearterialization leads to a definite but mild and reversible mitochondrial and cell membrane damage. The results indicate further the need of adequate controls when the effects of dearterialization on the liver are studied.

Alanine Transaminase↗
PubMed1978

Revascularization in mesenteric infarction by reimplantation of the superior mesenteric artery. Report of a case.

A case of revascularization in mesenteric infarction by reimplantation of the superior mesenteric artery combined with intestinal resection is presented. The patient had an acute occlusion of the superior mesenteric artery with coincident blockage of celiac axis and inferior mesenteric artery resulting in gangrene and perforation of the small bowel. The good postoperative recovery suggests the usefulness of this method in selected cases.

Aged↗